NGC 6210

NGC 6210 is a planetary nebula located in the constellation Hercules, approximately 5.4 ± 1.3 kly from the Sun.[2] It is positioned about 38° above the galactic plane at a vertical distance of about 3.3 kilolight-years (1 kpc) and thus has little extinction from intervening interstellar dust.[4] This object was first recorded as a star-like feature by Joseph Lalande on March 22, 1799. However, credit for the discovery of a nebula goes to Wilhelm Struve in 1825. John L. E. Dreyer described it as, "a planetary nebula, very bright, very small, round, disc and border".[5]

NGC 6210
Emission nebula
Planetary nebula
A Hubble Space Telescope (HST) image of NGC 6210
Credit: HST/NASA/ESA
Observation data: J2000 epoch
Right ascension16h 44m 29.51960s[1]
Declination+23° 47′ 59.4913″[1]
Distance5.4 ± 1.3 kly (1.7 ± 0.4 kpc)[2] ly
Apparent dimensions (V)40″ × 30″[2]
ConstellationHercules
DesignationsPN G043.1+37.7, BD+24° 3048, HD 151121, IRAS 16423+2353, NGC 6210[3]

This nebula is "very amorphous and irregular" in shape, but forms a rough ellipsoid.[4] It consists of two parts; a bright inner region filled with arches and filaments spanning 13″ × 16", and a larger and fainter outer volume that has a pair of "tubular" structures. The inner region has an expansion velocity ranging over 19–24 km/s.[2] The emission from the outer part of the nebula is only about 1% of the total.[4]

The central star has an apparent visual magnitude of 12.66 and the spectrum matches a hydrogen-rich star of type O(H). It has an estimated temperature of 65,000 K. The abundances of the nebula suggest a low initial mass for the central star, probably ~0.9 M☉.[4] Outflow from this star has been measured with velocities of 2,180 km/s, and the estimated mass loss rate is 2.2×10−9 M☉ yr−1. There appears to be a collaminated jet feature to the northwest, suggesting the central star is ejecting material along two and possibly four such directions.[6]

  • The center of NGC 6210

References
  1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. Bohigas, J.; et al. (February 2015). "Echelle spectroscopy and photoionization modelling of the entire planetary nebula NGC 6210". Monthly Notices of the Royal Astronomical Society. 447 (1): 817–835. Bibcode:2015MNRAS.447..817B. doi:10.1093/mnras/stu2389.
  3. "NGC 6210". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-02-26.
  4. Pottasch, S. R.; et al. (May 2009). "Abundances in the planetary nebula NGC 6210". Astronomy and Astrophysics. 499 (1): 249–256. Bibcode:2009A&A...499..249P. doi:10.1051/0004-6361/200911654.
  5. Seligman, Courtney. "New General Catalogue objects: NGC 6200 - 6249". cseligman.com. Retrieved 2020-09-20.
  6. Phillips, J. P.; Cuesta, L. (March 1996). "NGC 6210: an Observational Case Study of a Jet Emitting Source". Astronomical Journal. 111: 1227. Bibcode:1996AJ....111.1227P. doi:10.1086/117868.
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